A solid catalyst component that includes magnesium, titanium, an electron donor compound (e.g., phthalic ester), and a halogen atom as essential components has been known as a component of an olefin polymerization catalyst. Various olefin polymerization catalysts have been proposed that include the solid catalyst component, an organoaluminum compound, and an organosilicon compound.
Various compounds that include an electron-donating group (e.g., diether compound and carbonate ether compound) have been proposed as a substitute for the phthalic ester. A diether compound produces a highly active catalyst that provides moderately high stereoregularity, and ensures good copolymerizability and good hydrogen response. However, the resulting polymer has a narrow molecular weight distribution, and a low block ratio is obtained when implementing ICP polymerization. A carbonate ether compound provides high stereoregularity, and ensures a high block ratio when implementing ICP polymerization. However, the activity, the copolymerizability, and the hydrogen response achieved using a carbonate ether compound are poor as compared with those achieved using a diether compound.